There is no one standard "drop"
The amount that a bullet drops in X distance will be determined by the speed of the bullet.
Speed is determined by starting speed, and how much that speed degrades over distance- which will be determined by the drag created by a bullet THAT shape creates. Usually referred to as the ballistic coefficent of that bullet.
Of course, ALL bullets begin to fall towards the earth the instant they are fired (except bullets fired UP). They all fall at 32 ft per second per second. The quicker it gets there, and the better the BC, the less the drop. Yes can be done on paper (a slide rule would be better) but you will need a LOT of paper- it is not a simple math substitution type formula.
Makers have worked out paper tables to calculate drop and energy- and now have on line ballistic calculators. Military uses a small computer on the firearm for very long range work.
Suggest you run your calcs, print relevant parts, attach to stock with a couple of rubber bands.